Term
| What is the definition of pharmacodynamics? |
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Definition
| The study of the biochemical and physiological effects of drugs and their mechanisms of action |
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Term
| What physical characteristics of drug molecules determine binding specificity? |
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Definition
| Drug size, shape, stero-isomerism (only one optical isomer), and polarity |
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Term
| What pulls ligands closer to the receptor? What couples the ligand to the receptor? |
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Definition
| Ionic bonds bring the ligand close to the receptor, hydrogen or van der waals forces couple the ligand to the receptor |
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Term
| What is binding affinity (Kd) |
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Definition
| A measurement of how readily a molecule will bind to a receptor, also the concentration of drug required to bin 1/2 of the receptors in a fixed population (high Kd means low affinity) |
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Term
| What is the law of mass action? |
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Definition
L + R <-> LR* -> biological response
(L = ligand, R = receptor) |
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Term
| How does Le Chatelier's theory apply to receptor theory? |
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Definition
| A change in the concentration of the drug or the receptor will shift the biological response one way or another |
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Term
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Definition
| The strength of the attraction between a ligand and a receptor |
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Term
| How do you calculate the equilibrium disassociation constant (Kd) of affinity? |
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Definition
| Kd = [L][R]/[LR], you can find it on a graph by looking at the concentration of the drug required to occupy 50% of the receptors |
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Term
| What is efficacy in receptor theory? |
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Definition
| A characteristic property of a ligand to induce the receptor to adopt an active conformation to generate a biological response (varies between 0-1) |
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Term
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Definition
| A substance which binds to a receptor and produces a biological response |
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Term
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Definition
| Substance capable of generating the maximum biological response a system can achieve by activating 100% or less of the receptors, affinity and efficacy = 1 |
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Term
| What is a partial agonist? |
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Definition
| Substance that produces, even at its highest concentration and 100% receptor occupation, less than the maximum response achievable by a system, affinity is and efficacy are between 0-1 |
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Term
| What is an inverse agonist? |
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Definition
| A substance that produces a decrease int he basal activity of a system |
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Term
| What are allosteric agonists or enhancers? |
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Definition
| Chemical compounds that increase the affinity and/or efficacy of agonists for receptors by binding and altering receptor conformation |
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Term
| What are the different types of antagonists? |
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Definition
| Chemical and physiologica |
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Term
| What is indirect antagonism? |
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Definition
| A substance that inhibits a biological response by acting at a site beyond the receptor, can antagonize agonists acting through more than one receptor |
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Term
| What are competitive antagonists? |
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Definition
| Most common, endogenous agonists and exogenous antagonists compete for a binding site on the receptor, has affinity but no efficacy |
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Term
| What characterizes equilibrium competitive antagonists? |
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Definition
| Reversible, antagonism increases at increased concentrations, can be overcome by increasing the amount of agonists |
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Term
| What characterizes nonequilibrium competitive antagonists? |
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Definition
| Binds irreversibly to receptor via covalent bond, antagonism increases with concentration, cannot be overcome by increasing agonist amount |
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Term
| What distinguishes allosteric agonists? |
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Definition
| Reduces affinity or efficacy of agonists by binding receptors on sites distinct from the agonist binding site |
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Term
| What is a dose-response curve? |
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Definition
| Graphical representations of the relationship of the quantity of a substance (drug or ligand) to the graded effect that the substance has on a biological system |
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Term
| What is a graded response? |
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Definition
| A response is one that changes proportionately with each single dose of drug given with each dose producing a single tissue response |
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Term
| What do quantal dose-response curves represent? |
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Definition
| The "all or nothing" theraputic endpoints of a drug based on dosage |
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Term
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Definition
| A comparison of the relative effectiveness of drugs acting by similar mechanisms by comparing ED50 values |
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Term
| Intrinsic activity is another name for what? |
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Definition
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Term
| How is equilibrium competitive antagonism graphically represented? |
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Definition
| Rightward shift (apparent decrease in potency) of the dose-response curve while still being able to achieve a maximum response (albeit at a much higher dose of agonist) |
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Term
| How is nonequilibrium competitive antagonism graphically represented? |
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Definition
| Downward shift, maximum response is impossible to attain regardless of dose |
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Term
| What is indirect antagonism? |
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Definition
| Antagonist that inhibits the generation of a biological response by acting at some point down stream of the receptor (i.e. with components of its signal transduction cascade), can be reversible or irreversible |
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Term
| What receptors are adrenergic receptors? |
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Definition
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Term
| What receptors are serotonergic receptors? |
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Definition
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Term
| What receptors are muscarinic cholinergic (Ach) receptors? |
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Definition
| M1, M2, M3, M4, M5 receptors |
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Term
| What receptors are histamine receptors? |
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Definition
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